You should be able to find the Nissan part number for it here:
nissan-europe.epc-data.com
Pretty much any genuine Nissan part is available through these guys by mail order: (instead of fighting with the service desk at Nissan)
nissangenuine.com
I have used them to buy suspension parts for my Leaf like stub axle nut and cotter pins - just be very careful that you have the exact part number as searching for parts by name on this site will give loads of matches without indication as to which matches your exact car. So I use the first site to find and identify the part number and the second one to buy it by giving it the exact part number.
Nissan Leaf with ZE0 frame, 10.2010 - ... - Genuine parts
Nissan Leaf parts catalog. Spare parts for Leaf, ZE0 frame.
Pretty much any genuine Nissan part is available through these guys by mail order: (instead of fighting with the service desk at Nissan)
Every Available Genuine Nissan part Shipped Worldwide from the UK
Genuine discounted Nissan parts shipped worldwide from the UK.
I have used them to buy suspension parts for my Leaf like stub axle nut and cotter pins - just be very careful that you have the exact part number as searching for parts by name on this site will give loads of matches without indication as to which matches your exact car. So I use the first site to find and identify the part number and the second one to buy it by giving it the exact part number.